The present work deals with an experimental investigation of charging and discharging processes in thermal storage system using a phase change material PCM. Paraffin wax was used as the PCM which is formed in spherical capsules and packed in a cylindrical packed column which acted as an energy storage system. Air was used as the heat transfer fluid HTF in thermal storage unit. The effect of flow rate and inlet temperature of HTF on the time of charging and discharging process were studied. The results showed that the faster storage of thermal energy can be made by high flow rate of heat transfer fluid HTF and high inlet temperature of heat transfer fluid. It was found that at 65°C HTF inlet temperature, the melting and solidification processes accelerated by 27.9% and 57.14% respectively, when the flow rate was increased from 9 to 24 L/s. Also, when the HTF inlet temperature changed from 65°C to 80°C, the time needed to complete melting process decreased by 38.8%.
Aim: This abstract aims to highlight the critical nature of climate change as a pressing challenge facing humanity in the 21st century. It underscores the severe consequences it poses to essential facets of human existence, including water and energy resources, agricultural production, and the broader environmental systems. Method: The abstract primarily utilizes a descriptive approach to emphasize the impact of climate change on the Middle East, particularly the Arab region. It relies on a review of existing knowledge and data related to climate change and its effects on ecosystems and drought patterns. Results: The abstract outlines the direct and indirect repercussions of climate change on human life and the environment. It draws atten
... Show MorePiroxicam (PIR) is a nonsteroidal anti-inflammatory drug of oxicam category, used in gout, arthritis, as well as other inflammatory conditions (topically and orally). PIR is practically insoluble in water, therefore the aim is prepare and evaluate piroxicam as liquid self-nanoemulsifying drug delivery system to enhance its dispersibility and stability. The Dispersibilty and Stability study have been conducted in Oil, Surfactant and Co-surfactant for choosing the best materials to dissolve piroxicam. The pseudo ternary phase diagrams have been set at 1:1, 2:1, 3:1 as well as 4:1 ratio of surfactants and co-surfactants, also there are 4 formulations were prepared by using various concentrations of transcutol HP, cremophore EL and triacetin
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Background: The apical seal is the single most important factor in determining the success of surgical endodontics, the aim of this study was to compare the sealing ability of Mineral Trioxide Aggregate in three different cavity designs. Materials and Methods: Thirty extracted human single-rooted teeth were divided into three groups of ten teeth per group, a retrograde cavity preparation was carried out using a low speed handpiece and round bur with parallel walls in the first group, ultrasonic retrotip and unit in the second group and a low speed handpiece with a carbide inverted cone bur with undercuts in the third group, all the cavities were filled with MTA. microleakage was measured by dye penetration technique using methylene blue. Re
... Show MoreIn this paper, the penetration of the stone column was investigated in order to get the minimum length of the stone column above which the increase in length has little advantage. The effect of using different materials in column are also studied. The material used is granular of different angle of internal friction (). The results of the investigation indicated that the effect of stone column remains constant when the ratio of the thickness of the soft clay layer to the stone column’s diameter is more than 15. The results also indicated that a pronounced effect is obtained when the angle of internal friction of the stone column material is increased.
The nay is one of the important in stvument in Arabic music which is considered one of the oriental instruments used in the oriental music tect, and is also considered one of the basic instruments in Arabic music, It is used in many religious and mundane areas, through its expressive capabilities through which expression and conveyance of feelings to the recipient, despite their importance and role in music, and through the researcher's follow-up to this subject did not find a study on the potential capabilities of the machine. In view of the above, and given the importance of this subject at the researcher, the need arose for research to study (the potential of the flute machine)..
This study examines the causes of time delays and cost overruns in a selection of thirty post-disaster reconstruction projects in Iraq. Although delay factors have been studied in many countries and contexts, little data exists from countries under the conditions characterizing Iraq during the last 10-15 years. A case study approach was used, with thirty construction projects of different types and sizes selected from the Baghdad region. Project data was gathered from a survey which was used to build statistical relationships between time and cost delay ratios and delay factors in post disaster projects. The most important delay factors identified were contractor failure, redesigning of designs/plans and change orders, security is
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This paper deals with a method called Statistical Energy Analysis that can be applied to the mechanical and acoustical systems like buildings, bridges and aircrafts …etc. S.E.A as a tool can be applied to the resonant systems in the circumstances of high frequency or/and complex structure». The parameters of S.E.A such as coupling loss factor, internal loss factor, modal density and input power are clarified in this work ; coupled plate sub-systems and explanations are presented for these parameters. The developed system is assumed to be resonant, conservative, linear and there is an equipartition of energy between all the resonant modes within a given frequency band in a given sub-system. The aim of th
... Show MoreThis study aims to calculate the percentage of loss and its causes of the horticultural crops tangerines and Seville oranges in Baghdad governorate for the 2020 agricultural season and estimate the economic impacts of losses both crops tangerines and Seville oranges at the study samples level. The research followed both methods descriptive and the quantitative mathematical in estimating the loss of horticultural crops from tangerines and Seville oranges trees and calculating the economic impact of this loss. The results showed that the percentage of losses of tangerines and Seville oranges crops on the level of wholesalers was about 12% and 13% respectively; causing economic losses estimated at about 3184.41 Euro. The results also displayed
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The current research aims to study the extent to which the Independent High Electoral Commission applies to information security risk management by the international standard (ISO / IEC27005) in terms of policies, administrative and technical procedures, and techniques used in managing information security risks, based on the opinions of experts in the sector who occupy positions (General Manager The directorate, department heads and their agents, project managers, heads of divisions, and those authorized to access systems and software). The importance of the research comes by giving a clear picture of the field of information security risk management in the organization in question because of its significant role in identifying risks and s
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